<?php

 $zero1=date(“y-m-d h:i:s”);

 $zero2=”-- ::′;

 echo “zero1的时间为：”.$zero1.”<br>”;

 echo “zero2的时间为：”.$zero2.”<br>”;

 if(strtotime($zero1)<strtotime($zero2)){

  echo “zero1早于zero2′;

 }else{

  echo “zero2早于zero1′;

 }

 ?>  

<?php

$zero1=strtotime (date("y-m-d h:i:s")); //当前时间  ,注意H 是24小时 h是12小时

$zero2=strtotime ("2014-1-21 00:00:00");  //过年时间，不能写2014-1-21 24:00:00  这样不对

$guonian=ceil(($zero2-$zero1)/); //60s*60min*24h

echo "离过年还有<strong>$guonian</strong>天！";

?>  

<?php

//PHP计算两个时间差的方法

$startdate="2010-12-11 11:40:00";

$enddate="2012-12-12 11:45:09";

$date=floor((strtotime($enddate)-strtotime($startdate))/);

$hour=floor((strtotime($enddate)-strtotime($startdate))%/);

$minute=floor((strtotime($enddate)-strtotime($startdate))%/);

$second=floor((strtotime($enddate)-strtotime($startdate))%%);

echo $date."天<br>";

echo $hour."小时<br>";

echo $minute."分钟<br>";

echo $second."秒<br>";

<?php

/**

 * 时间差计算

 *

 * @param Timestamp $time

 * @return String Time Elapsed

 * @author Shelley Shyan

 * @copyright http://phparch.cn (Professional PHP Architecture)

 */

function time2Units ($time)

{

   $year   = floor($time /  /  /  / );

   $time  -= $year *  *  *  * ;

   $month  = floor($time /  /  /  / );

   $time  -= $month *  *  *  * ;

   $week   = floor($time /  /  /  / );

   $time  -= $week *  *  *  * ;

   $day    = floor($time /  /  / );

   $time  -= $day *  *  * ;

   $hour   = floor($time /  / );

   $time  -= $hour *  * ;

   $minute = floor($time / );

   $time  -= $minute * ;

   $second = $time;

   $elapse = '';

   $unitArr = array('年'  =>'year', '个月'=>'month',  '周'=>'week', '天'=>'day',

                    '小时'=>'hour', '分钟'=>'minute', '秒'=>'second'

                    );

   foreach ( $unitArr as $cn => $u )

   {

       if ( $$u >  )

       {

           $elapse = $$u . $cn;

           break;

       }

   }

   return $elapse;

}

$past = ; // Some timestamp in the past

$now  = time();     // Current timestamp

$diff = $now - $past;

echo '发表于' . time2Units($diff) . '前';  特别注意：<?php echo time2Units(time()-$row['date']).'前'?> 

?>